nodule (redirected from nodulus)

nodule: see concretion.

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nodule

In geology, a rounded mineral concretion that is distinct from, and may be separated from, the formation in which it occurs. Nodules usually are elongated and have a knobby irregular surface; they are generally oriented parallel to the bedding. Chert and flint, clay ironstone, and phosphorites commonly occur as nodules. Manganese-rich nodules are found on the ocean floor.

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nodule

1. any of the knoblike outgrowths on the roots of clover and many other legumes: contain bacteria involved in nitrogen fixation

2. Anatomy any small node or knoblike protuberance

3. a small rounded lump of rock or mineral substance, esp in a matrix of different rock material

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nodule [′näj·ül]

(anatomy)

A small node.

A small aggregation of cells.

(botany)

A bulbous enlargement found on roots of legumes and certain other plants, whose formation is stimulated by symbiotic, nitrogen-fixing bacteria that colonize the roots.

(geology)

A small, hard mass or lump of a mineral or mineral aggregate characterized by a contrasting composition from and a greater hardness than the surrounding sediment or rock matrix in which it is embedded.

(medicine)

A primary skin lesion, seen as a circumscribed solid elevation.